Patents by Inventor Naoto Nagaosa

Naoto Nagaosa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7037807
    Abstract: A device and a method for generating an electric-field-induced spin current are disclosed. A highly spin-polarized electric current is generated using a semiconductor structure and an applied electric field across the semiconductor structure. The semiconductor structure can be a hole-doped semiconductor having finite or zero bandgap or an undoped semiconductor of zero bandgap. In one embodiment, a device for injecting spin-polarized current into a current output terminal includes a semiconductor structure including first and second electrodes, along a first axis, receiving an applied electric field and a third electrode, along a direction perpendicular to the first axis, providing the spin-polarized current. The semiconductor structure includes a semiconductor material whose spin orbit coupling energy is greater than room temperature (300 Kelvin) times the Boltzmann constant. In one embodiment, the semiconductor structure is a hole-doped semiconductor structure, such as a p-type GaAs semiconductor layer.
    Type: Grant
    Filed: December 24, 2003
    Date of Patent: May 2, 2006
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Shuichi Murakami, Naoto Nagaosa, Shoucheng Zhang
  • Patent number: 6985276
    Abstract: A magnetooptic element whose size is essentially that of a lattice, namely several angstroms in size of magnetic material and which at the same time has its exhibiting magnetooptic effect detectable is provided along with a magnetooptic disk, a memory device and a magnetooptical picture or image display with a storage capacity of several terabits per square inch or more, each using such a magnetooptic element. The magnetooptic element utilizes a gigantic effective magnetic filed based on a spin chirality formed by geometrically configuring the spin orientation and crystallographic structure of a certain solid material.
    Type: Grant
    Filed: March 20, 2002
    Date of Patent: January 10, 2006
    Assignees: National Institute of Advanced Industrial Science and Technology, Japan Science and Technology Agency
    Inventors: Yasujiro Taguchi, Yoshio Kaneko, Yoshinori Tokura, Naoto Nagaosa
  • Publication number: 20040245510
    Abstract: A magnetooptic element whose size is essentially that of a lattice, namely several angstroms in size of magnetic material and which at the same time has its exhibiting magnetooptic effect detectable is provided along with a magnetooptic disk, a memory device and a magnetooptical picture or image display with a storage capacity of several terabits per square inch or more, each using such a magnetooptic element. The magnetooptic element utilizes a gigantic effective magnetic filed based on a spin chirality formed by geometrically configuring the spin orientation and crystallographic structure of a certain solid material.
    Type: Application
    Filed: March 19, 2004
    Publication date: December 9, 2004
    Inventors: Yasujiro Taguchi, Yoshio Kaneko, Yoshinori Tokura, Naoto Nagaosa